[R-390] Dead R-390A power supplies

[Steve Hobensack]

For me, building power supplies is fun. All it takes is a basic knowledge of electronics (if that). Substitute transformers can be found at reasonable cost.  An outboard HB supply might be a good thing. The rx will run cooler, and there would be no acoustic coupling of hum into the pto shaft. I have done this with other receivers that could have gone to the grave yard. Big improvement, especially stability.

I may have posted this before. R390a power supplies have been chucked into the can because of an apparent shorted transformer. The short might be a carbon track in the potting tar right at the high tension winding porcelain insulator. Its a fairly easy fix. Look for it.

Steve N8YE